The invention is based on a robot arm with an assembly flange for tools. In a known robot arm of this generic type (DE-Al 33 40 912), the assembly flange is constructed as a supporting basic element of a gripper exchange system which is matched with the gripper tools used in this system with respect to the mechanical centering and fastening means as well as the line connections for power supply and control and therefore forms a part of a special structural component which is not suitable for the assembly of other tools.